The present invention relates to printing machines general, and more particularly to an ink dosage system therefor. Even more particularly, the invention pertains to an adjustment device for adjusting ink gaps in ink zones formed between the doctor blade and the doctor roller in the printing machine, especially for the rotary printing machine with a divided or undivided doctor blade.
One of adjustment devices of the type under discussion has been disclosed in German patent publication DD-PS 139,114. The disclosed adjustment device for adjusting the position of the ink blade relative to the doctor roller in the printing machine includes a motor connected to a special gear train which drives the ink zone adjusting screw for adjusting the position of the doctor blade. A potentiometer and an indicator serve in the known device for measuring and indicating respective positions of the ink zone adjusting screw. The disadvantage of this otherwise satisfactory adjustment device resides in that in the case of wearing off the doctor blade, the adjusted zero or initial position of the doctor blade, corresponding to a minimal distance between the doctor blade and the doctor roller is drifted under mechanical loads to which the doctor blade is subjected. However, without an electrical readjustment of the potentiometer in respect to the ink zone-adjusting screw it was impossible or extremely time-consuming to adjust the doctor roller, and the adjustment of the doctor blade according to real working conditions was almost impossible also.